Instrumental Activities of Daily Living in Older Adults with Epilepsy: A Cross-Sectional and Longitudinal Multicenter...

Instrumental activities of daily living (IADLs) represent a critical but understudied measure of day-to-day function in persons with epilepsy(PWE). In the multicenter Brain Aging and Cognition in Epilepsy (BrACE) study of PWE aged ≥55 years, we examined the proportion, clinical correlates, epilepsy-related predictors, and longitudinal trajectory of IADL impairment.

IADLs were assessed using the Functional Activities Questionnaire(FAQ; range=0-30; higher=more impaired); FAQ≥2 defines MCI-level impairment and FAQ≥5 dementia-level functional impairment. Multivariable logistic regression identified predictors of baseline function. Global cognition (Montreal Cognitive Assessment [MoCA]), individual cognitive measures, and quality of life (QOL) were compared between the impaired and unimpaired groups. Linear regression evaluated predictors of longitudinal functional decline.

Of 57 participants(mean age=66.6±7.2 years; female=52.6%), 38.6%(n=22) had MCI-level functional impairment and 17.5%(n=10) had dementia-level functional impairment. In univariate analyses, worse FAQ scores were associated with lower education, higher area deprivation index, early-onset epilepsy (EOE < 60 years), antiseizure medication polytherapy, and epilepsy localization (all p < 0.05). In multivariable analysis, temporal lobe epilepsy (OR=4.46, 95%-CI=1.09-21.83,p=0.047), EOE(OR=7.14,95%-CI=1.16-59.97,p=0.046), and lower education(OR=0.70,95%-CI=0.49-0.93,p=0.025) remained independently associated with baseline MCI-level functional-impairment. Lower education (OR=0.55,95%-CI=0.29-0.84, p=0.021) was the only factor associated with dementia-level IADL-impairment. IADL-impaired participants demonstrated lower verbal memory scores(adjusted-p=0.041) and MoCA(adjusted-p<0.001), particularly in visuospatial/executive function, attention, and memory subscores, and worse QOL(adjusted-p=0.041). IADL-impairment was greatest in financially-mediated and memory-dependent tasks.Longitudinally, EOE(β=7.51,95%-CI=1.92-13.10,p=0.017) and older age(β=0.38,95%-CI=0.12-0.65,p=0.012) predicted greater functional decline. Nearly one-third progressed to significantly worse function over a two-year period, with 15.4% progressing from MCI-level to dementia-level impairment and 15.4% from normal function to MCI-level IADL-impairment.

Functional impairment affects ∼40% of older PWE, with ∼1-in-6 experiencing functional impairment comparable to overt dementias. Temporal lobe localization, EOE, lower education, and poorer cognition are important determinants of baseline functional status. EOE and older age predict accelerated functional decline, suggesting that cumulative disease burden and aging-related processes may drive functional deterioration. These findings provide one of the first epilepsy-specific longitudinal characterizations of IADL impairment and support routine functional assessment in PWE.

- Functional impairment is common in older PWE, affecting ∼ 40%, with 1 in 6 showing dementia-level functional impairment. - Temporal lobe epilepsy localization, early-onset epilepsy, and lower education are independently associated with baseline MCI-level functional impairment.- Lower education was the only independent predictor of dementia-level IADL impairment.- IADL impairment was associated with worse verbal memory, global cognition, and quality of life.- Over two years, early-onset epilepsy and older age predicted greater functional decline, with nearly one-third progressing to worse functional status.